In the UK, we will never get bored with the weather, it is always changing. In The Lakes for example you can have four seasons in one day. If you have the correct clothing, you can walk in all weathers although consideration is always required especially where snow, ice, fog or floods are forecast.
Cooler weather is often better for walking, but cold at street level can become bitter at heights. Hot weather is great for the beach or garden but not so good walking as counter intuitive as it may sound; you will get sweaty and your energy feels like it is being sapped. My optimum walking temperature is between 4˚C and 18˚C.
Snow and Ice
The natural beauty of snow and ice speak for themselves. Most landscapes can look even more spectacular when covered in snow. There is no reason to let snow (fallen snow) stop you from walking providing you have the right clothing and footwear. Steep paths should really be avoided and ridges become a no-go. The chance of slipping increases so take precautions and leave yourself more time to do a walk so that you get around the route safely.
Snow can obscure drops and water so keep to the paths, if you cannot see the path then you should not be walking.
If it is snowing when you start your walk or starts snowing before you get to half way it is better to turn back and be safe. Always stay on well visited routes.
It is dangerous to walk in foggy conditions as it is easy to get lost. However, on some walks fog can draw in quickly and unannounced. Should this happen turn back and retrace your steps.
Rain is common on any walk, pack a rain coat and either waterproof or quick drying trousers and a change of clothes. The best way to avoid rain is to study the weather forecast and try chose a dry day.
Walking in the dark is not advisable and should only be done in a guided night walk group.